"Ringing the changes" is an expression which comes from playing tunes on church bells, especially in cathedrals with eight bells in their towers. Don't look for this
expression in this week's OVI extracts - I only mention it because of its meaning, which is that when you have a limited number of words to express related ideas, you have to "ring the changes"
with these words, that is to say you have to use them in different alternations to create a text which sounds nice, without too much boring repetition.
So when I have to deal with a carousel of "preteky", "zápas", "súťaž", "turnaj", "majster" and "olympiád", I use the words "race", "match", "competition" (or "event"
for extra variety), "tournament", "championship" and "Olympiad" (although strictly speaking in English this means the intervening period, e.g. four years, between successive Olympic Games, not the
games themselves), not in this order of increasing size, but in various combinations to avoid repetition.